The subject disclosure relates to quantum computing, and more specifically, to techniques facilitating qubit design and fabrication for quantum computers.
As computer technology advances and conventional computing devices decrease in physical scale, a growing interest has been placed on quantum computing as a technique by which computing technology can continue to advance past the physical limitations of traditional computers. A quantum computer can operate via superconducting quantum logic circuits, which can include arrays of qubits linked by quantum buses. One type of qubit that can be utilized is the transmon qubit, which is discussed by Koch et al., “Charge-insensitive qubit design derived from the Cooper pair box,” Phys. Rev. A 76, 042319 (2007). As discussed by Koch et al., “[a] transmon consists of two superconducting islands coupled through two Josephson junctions, but isolated from the rest of the circuitry.” Koch et al. further discusses that a transmon includes “a shunting connection of the two superconductors via a large capacitance CB accompanied by a similar increase in the gate capacitance Cg.”
The capacitances associated with transmon qubits can result in radiation losses and crosstalk between separate qubits and far-field radiation emitted from individual qubits, which can both have an adverse impact on qubit circuit size and efficiency. A technique for reducing crosstalk between different qubits is discussed by Abraham et al., “SYMMETRIC PLACEMENT OF COMPONENTS ON A CHIP TO REDUCE CROSSTALK INDUCED BY CHIP MODES,” U.S. Pat. No. 8,972,921. Abraham et al. discusses reduction of inter-qubit crosstalk via                a chip comprising two circuits arranged as mirror images of each other on a substrate. Each of the circuits . . . includes three qubits that are interrogated by microwave pulses through their interaction with microwave resonators or harmonic oscillators that store RF energy. The circuits also each include five ports through which drive signals are introduced and output signals of the circuit are received”(reference numerals omitted). With respect to far-field radiation emitted by an individual qubit, however, there exists a need in the art for techniques to improve the size and efficiency of a multi-qubit circuit via reduction of said radiation.        